This fixes Mono's Windows serial support for COM10+, while also not breaking compatib...

diff --git a/mcs/class/System/System.IO.Ports/WinSerialStream.cs b/mcs/class/System/System.IO.Ports/WinSerialStream.cs
index e29aca4722fff3a6da236519f9eecc4219661e76..280082a706a7b008c4ae6a70faa379d082257a5e 100644 (file)
--- a/mcs/class/System/System.IO.Ports/WinSerialStream.cs
+++ b/mcs/class/System/System.IO.Ports/WinSerialStream.cs
@@ -78,7 +78,9 @@ namespace System.IO.Ports
                                bool dtr_enable, bool rts_enable, Handshake hs, int read_timeout, int write_timeout,
                                int read_buffer_size, int write_buffer_size)
                {
-                       handle = CreateFile (port_name, GenericRead | GenericWrite, 0, 0, OpenExisting,
+                       handle = CreateFile (port_name != null && !port_name.StartsWith(@"\\.\")
+                                       ? @"\\.\" + port_name : port_name,
+                                       GenericRead | GenericWrite, 0, 0, OpenExisting,
                                        FileFlagOverlapped, 0);
 
                        if (handle == -1)